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arXiv · 1403.5773

MicroSQUID Force microscopy in a dilution refrigerator

Danny Hykel·Zhao-Sheng Wang·Pauline Castellazzi·Thierry Crozes·Gorky Shaw·Klaus Hasselbach·K. F. Schuster
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Abstract

We present a new generation of a scanning MicroSQUID microscope operating in an inverted dilution refrigerator. The MicroSQUIDs have a size of 1.21$ \ μ$m\textsuperscript{2} and a magnetic flux sensitivity of 120 $μΦ_{0} / \sqrt{\textrm{Hz}}$ and thus a field sensitivity of %$550^{-6} \ Φ_{0} / \sqrt{\textrm{Hz}}$ 550$ \ μ\textrm{G}/ \sqrt{\textrm{Hz}}$. The scan range at low temperatures is about 80 $μ$m and a coarse displacement of 5 mm in x and y direction has been implemented. The MicroSQUID-to-sample distance is regulated using a tuning fork based force detection. A MicroSQUID-to-sample distance of 420 nm has been obtained. The reliable knowledge of this distance is necessary to obtain a trustworthy estimate of the absolute value of the superconducting penetration depth. An outlook will be given on the ongoing direction of development.

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Danny Hykel, Zhao-Sheng Wang, Pauline Castellazzi, Thierry Crozes, Gorky Shaw, Klaus Hasselbach, K. F. Schuster. 2014-03-23. MicroSQUID Force microscopy in a dilution refrigerator. https://doi.org/10.1007/s10909-014-1174-9

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